Process for refining petroleum oils



Dec. 11, 1945 F. w. BRETH ETAL PROCESS FOR REFINING PETROLEUM OILS Original Filed March 14, 1939 FIG. 7|

BAUXITE ORE FURNAC E DE-DUSTER DE- DUSTED BAUXITE STORAGE TANK DUST FIG.

BAUX [TE 2 Sheets-Sheet l ORE FURNACE 600F. MAX. TEMP.

REDUC ING MAGNETIC ATMOS PHER 1 SE PARATOR MAGNETIC DISCARD R EDUCED IRON CONTENT BAUXITE FURNACE I200 F TEMP.

OXIDIZING ATMOSPHERE DE-DUSTER DE-DUSTED STORAGE DUST BAUXIT E ANK ' INVENTORS FERDINAND w. ERETH ANTHONY KINSEL AT ORNEY) Dec. 11, 1945. F. w. BRETH EIAL 2,390,917

PROCESS FOR REFINING' PETROLEUM 01145 Original FiI ed March 14, 1939 2 Sheets-Sheet 2 FIGS ( BAUXITE (z) FILTERING STOCK (on. COLORING MATTER) (4) a uxaTE COLORING MATTER RETAINED OIL (5) AIR BAUXITE COLORING I RETA'NED MATTER RETAINED on.

(7) NAPHTHA WASH (I3) WASHOUT (NAPHTHA on.)

-(e) aAux|TE COLORING MATTER NAPHTHA DISTILLATION (s) STEAM o|| NAPHTHA NAPHTHA WASH (lo) BAUXITE COLORING MATTER (:4) STEAM EXTRACT (H) REGENERATION (NAPHTHA WATER OIL) SETTLING V v (I2) REGENERATED BAUXITE OIL NAFHTHA WATER IJR N OFF DISTILLATION OIL NAPHTHA NAPHTHA WASH FERDINAND W ERETl-l ANTHONY KINSEL BY M ATTORNEY Patented Dec. 11, 1945 PROCESS FOR REFINING PETROLEUM OILS Ferdinand W. Broth and Anthony Kinsel, Pe-

trolia, Pa., assignors to L. Sonnebom Sons, Inc., New York, N. Y., a corporation of Delaware Original application March 14, 1939, Serial No.

261,790. Divided and this application October 2, 1943, Serial No. 504,808

4 Claims. (01. 196-147) This invention relates to new and useful improvements in the refining of petroleum hydrocarbons.

The present application is a division of our application Serial No. 261,790, filed March 14, 1939,

entitled Bauxite adsorbents and processes of making and using same.

The conventional liquid phase refining treatment of petroleum hydorcarbons including residue and distillates, such as kerosene, gasoline, lubricating oils, transformer oils, medicinal oils, petrolatum, paraflin, etc., generally involves the use of solid adsorbent materials to improve the color of such products and/o to effect a partial desulphurization of the same, For this purpose the hydrocarbons are brought into contact with the adsorbent material. This may be accomplished in various ways, such as by admixing the adsorbent material in a finely divided form with the hydrocarbon to be refined and thereafter separating the mixture by means of a filter press .whlch retains the adsorbent material, which process is commonly referred to as contacting,"

or, alternatively, by passing the hydrocarbon material through a bed of the adsorbent from which it issues in a decolorized condition. The latter procedure is commonly referred to as percolation." If the hydrocarbon to be refined is solid or semi-solid at ordinary temperatures, such as petrolatum, and like substances, it is contacted with the adsorbent material, preferably removal of colorless compounds which are con-- verted to visible coloring matter by the polymerizing action of the adsorbent. material. The ad-' sorbent material principally used in the industry in the percolation method is generally a clay of the fullers earth type which has been specially processed to develop its adsorbent characteristics; for example, it may be subjected to heat or acid treatment or both.

' Percolation through bauxite has been used to some extent for the refining of some petroleum hydrocarbons. Bauxite, however, as it is btained from the mine, possesses only very weak adsorbent properties, and acquires enhanced adsorbent properties only after heat treatment which is generally referred to in the industry as the activation of the bauxite.

The activation of the bauxite is usually carried a general diminution in "size of the particles subout by heating th same to temperatures of the order of from 600 to1600 F. Such treatment imparts to the bauxiteenhanced adsorptive properties which may be regenerated after the bauxite becomes exhausted during use, by again roasting same at temperatures of the order of the magnitude aforesaid We have discovered th'at the adsorptive characteristics of bauxite may be substantially increased by selecting a. bauxite of a particular predetermined type, and subjecting it to a special activation treatment. A bauxite of improved activity results, and when used in the refining of petroleum oil products, it will not only give higher yields but will also furnish products of a higher degree of purification than could be obtained with a bauxite selected and activated in accordance with hitherto l-mown practices.

The bauxite used in accordance with our invention is preferably a bauxite having at least 20% by weight of water of constitution and having a particle size predominantly between 20 and mesh.

Suitable bauxites possessing such desired characteristics are found, for instance, among the bauxites containing water of constitution above 20%, such as Arkansas bauxites with a water of constitution of from approximately 29 to 30%, bauxites from India of about 23.8% water of constitution, bauxites from Alabama with a water of constitution between 25 and 30%, bauxites from Georgia with a water of constitution between 29.1 and 33.5%, etc. It is of course understood that the water of constitution is not critical and that bauxites with lower percentages may be used, provided they exhibit the afore-mentioned characteristics, though we have found as a gen-- eral rule that bauxites possessing such characteristics and having at the same time a water of constitution of at least 20% will give best results.

In the refining of hydrocarbons derivedfrom petroleum oils by percolation through bauxite, we prefer to use a range of particle size between 20 and 80 mesh. Particles coarser than 20 mesh, as a general rule, do not exhibit the high adsorptive eificiency necessary for successful percolation, whereas particles smaller than 80 mesh, though possessing adsorptive characteristics to a high degree, will give unsatisfactory yields as a result of increased soakage, and furthermore will result in the formation of filter beds so densethat the percolation rate is materially impaired.

During the activation of bauxite by heat treatment at temperatures between 600 and 1600; F.,

iected to the treatment occurs and an appreciable amount of fine particles below 80 mesh is produced. We have found that, though most of these particles, that may be termed for p p se of convenience bauxite dust," are removable by mechanical means, such as screen sifting and the like, comparativel large amounts are retained by the coarser bauxite particles and defy attempts or removal heretofore suggested. We have discovered that this phenomenon is due to the fact that an activated bauxite possesses a pronounced power of attraction for its own dust, and will usually exercise this power of attraction to the extent of causing retention of up to of bauxite dust (calculated on the total amount of bauxite present after separation of the conventionally removable dust). We have found that the adsorptive efficiency of activated bauxite of a particle size between and 80 mesh for the refining of hydrocarbon products is greatly impaired and materially reduced by reason of these dust particles which tenaciously adhere to the particles of larger size despite the fact that the dust particles, as such, inherently possess an adsorptive eiliciency which is superior to that of bauxite particles of coarser mesh size. The adsorptive efficiency of bauxite particles of a size between 20 and 80 mesh progressively decreases with the presence of increasing amounts of particles smaller than 80 mesh until a ,minimum is reached at a point where the dust content of the bauxite reaches approximately 10%. With higher dust contents the adsorptive efficiency again commences to increase as the amount of dust present in excess of approximately 10% commences to add its inherent adsorptive efficiency to that of the coarser bauxite particles, the efficiency of which is impaired by reason of the first 10% dust found to be tenaciously adhering to the coarser particle's. With a dust content of approximately the adsorptive eiiiciency of the dust containing bauxite will have again reached the adsorptive efficiency of substantially completely dedusted' bauxite, and will further increase with increasing dust content. Though from the standpoint of adsorptive efilciency the presence of large amounts of dust may be desirable, we have found that dust will interfere .with the successful percoiation treatment to such an extent that the removal of the dust present in excess of 15 and preferably-in excess of 10% is a prerequisite to successful bauxite filtration with regard to filtration yield and rate of flow of the hydrocar= bon material through the filter bed.

In the following table, the adsorptive efficiency of a 'bauxite of a particle size between 20 and 80 mesh and containing varying amounts of dust, is shown:

As shown in the table, the adsorptive efficiency of the bauxite or the dust (la t 1191'! zontal column), respectively, is expressed in terms of gravity test; The term "gravity test" of a particular adsorbent material, as developed by one of us to express-adsorptive'efliciency of such material, connotes, with the omission of decimals, the difference between the respective specific gravities of the hydrocarbon material to be refined before and after its filtration through the adsorbent. Since for a successful percolation treatment a dust content in excess of 15% and preferably in excess of 10% isundesirable, and-since up to 10% of dust content constitutes an impairment of the adsorptive eificiency of the filter material, it is requisite for efllcient percolation operations to remove sub stantially all of the dust including the portion adhering to the coarser particles.

We have discovered that the attractive power of the bauxite for its own dust varies with certain temperatures and that a temperature range of minimum attraction exists within which the attractively adhering bauxite dust may be removed from the bauxite by suitable means, such as a blast or current of air or other suitable gas. This temperature range of minimum attraction of bauxite for bauxite dust lies between 500 and 1600 F., and preferably between 600 and -1200 F. when blowing air over or through the bauxite within this temperature range and preferably in countercurrent fashion, the attractively adhering bauxite dust is substantially completely removed, and we have termed and will hereafter refer to such temperature ranges as the effective dedusting temperature range" of the bauxite. For the purpose of preventing the cooling of the bauxite to below the-effective dedusting temperature range prior to the substantially complete removal of attracted dust, we prefer to preheat the air before blowing the same over or through the bauxite, and have found that best results and a substantially dust-free bauxite are obtained by not only maintaining the bauxite within the effective dedusting temperature range but also passing the air over or through the bauxite after the air has been heated to a temperature of at least 120 1!, and

preferably of at least 220 F. The current or blast of air or other suitable gas passing over or through the bauxite should have a velocity sufficient to remove, the dust particles from the bauxite while the same is within the effective dedusting temperature range. With air velocities of from 4 to 6 feet/sec, and a preferred velocity of 5 feet/see, satisfactory results are obtained.

The conditioning of bauxite in accordance with our invention is preferably carried out in the following manner: The bauxite ore is roasted in accordance with conventional practice by heating the same in a suitable furnace or kiln, such as a Herreshoif type furnace, a rotary kiln, a

vertical stationary furnace, or the like, to a temperature of from 600 to 1600 1".. and preferably to a temperature of from 1000 to 1200' F. During this heating or calcining operation, sumcient air is admitted to give at all times and to all parts of the furnace good oxidizing conditions. The calcined bauxite when removed from the calcining furnace preferably a temperature in excess of 1000' F., and is now subjected to the dedusting treatment which is preferably carried out in a closed receptacle through which a stream of hot bauxite is passed either in a vertical column by means of gravity, as for instance in cascade fashion or, horizontally by means of conveyors, being met in its travel and while its Stabilized bauxite.

'the processing and subsequent regeneration of the same, an attrition test is performed. This attrition test is executed by placing the material to be tested in a cylindrical can having a diameter of 6% inches and a heightof inches and con- -taining approximately 5 steel balls ()6 inch in diameter, 8 grams apiece); the cylindrical can is then rotated for A hour on a shaking machine or similar device at approximately 60 R. P. M. In this treatment the pounding of the steel balls will give rise to dust formation and the dust so formed furnishes an indication of the dust-forming tendencies of the original material.

The friability number connotes the 100 multiple of the difierence between the mean mesh of a particular sample before and after attrition.

The dust number connotes the 100 multiple of the diii'erence in per cent by weight of dust present after and before attrition.

In Table III below, a comparison of friability and dust numbers of unstabilized activated bauxite and of bauxite stabilized in accordance with our invention is given. The table further sets forth for the respective bauxites, the total amount of dust present after each of a number of successive regenerations:

Table III Regeneration! conventionally sctivated bauxite.. 02.17

In the aforementioned procedure for the reduction of the friability of a bauxite, though the dust formed during the first activation and prior to its contact with a hydrocarbon material may be removed if desired; it is not necessary to do so as the adsorptive efllciency of such activated bauxite, even though impaired, is sufiicient for the adsorption of an amount .of hydrocarbon material necessary for carbonization and the reduction of the ferriferous material to para-magnetic form. Thedust present in the freshly activated bauxite may be conveniently carried, therefore, through the succeeding steps of the process, and may removed together with the dust formed during the subsequent treating steps, 1. e., heat reduction and oxidative carbonization, in one single. dedusting operation in the manner hereinabove set forth.

Instead of contacting the first activated bauxite but once with a hydrocarbon material, it is of course possible and frequently of advantage touse the so activated bauxite as a filtering material, i. e., repetitiously contacting thesame with a suitable hydrocarbon material to be refined until its adsorptive properties are substantially exhausted and to thereafter subject the same to the procedure outlined in connection with the removal of ferriferous matter, followed by oxidative calcination and dedusting; If the bauxite is first used as a filtering material until its exhaustion, prior to the removal of ferriferous matter therefrom, it is of advantage to remove the sometimes rather high amounts of unadsorbed but mechanically. retained hydrocarbon material by washing with a suitable solvent and preferabl a hydrocarbon solvent boiling predominantly below 400' It. such'as'naphtha and the like, as the actually adsorbed matter is'usually mass rmthe reduction of the ferriferous material into paramagnetic form. Without such prior removal the retained hydrocarbon material would be wasted Its presence may even be harmful as the oxidation of the same during the calcining step is emthermic in nature, thereby tending to increase dust formation. In this combined activation and stabilization of the bauxite, as high as 'l to 10% of dust and approximately 3 to 8% of ferriferous matter is removed (both figures being calculated on the basis of the'weight of the original ore) In the store-described stabilization treatment of a bauxite, ferriferous matter is not entirely removed. Though the remaining ferriferous matter is not sufiiciently large in amount to either impair the adsorptive efilciency of the bauxite during the succeeding uses or to cause excessive dust'iormation'during the succeeding regenerations, we have observed that after a comparative- 1y large number of regenerations and reuses, say

40 to 50 calcinations. this ferriferous matter will ous oxidative regenerations without resort to a treatment under reducing conditions.

In the refining of hydrocarbon products in ac-' cordance with our invention, the material is contacted with a bauxite suitably conditioned as hereinbeforc set forth by percolating the hydro carbon material in liquidform through a bed of such bauxite. The percolation may be accomplished either at atmospheric pressure or at subatmospheric or superatmospheric pressure. Superatmospheric pressure proves advantageous in many instances and particularly in'the refining of petrolatum and the like materials.

It is sometimes desirable to dilute the hydrocarbonmaterial with a suitable diluent so as to reduce viscosity and facilitate the contact between the adsorbent and the material to be refined. Such procedure is particularly to be rec- V ommended in the case of the more viscous hydroicarbons as it will improve the fiow of the same through the filter bed and decrease excessive retention thereon. Diluents that may be used for facilitating contact with the bauxite should have a suificiently high boiling point to prevent losses during the contact treatment and a sufilciently low end pointso that their removal from the refined product does not necessitate the use of iniuriously high temperatures, and they should be furthermore substantially free from a displacing or solvent action upon adsorbed coloring matter.

A suitable diluent is, for instance, one with aninitial boiling point'of from to F., and an end point of from 360 to 390 R, such as naphtha and similar low boiling hydrocarbons. As a eneral rule dilution of the stock to be refined is advisable with stocks of a Baybolt universal viscosity at 210 I"., between 60 and 100 seconds. and should be used in order to obtain best results with stocks of a Baybolt universal viscosity at 210 F., above 106 seconds; stocks of a Saybolt universal viscosity at 210' E, below 60 seconds should be contacted straight, i. e., without dilution. 60 to '10 parts ofdiluent to 40 to 30 parts ofoilstockshouldbeuscdwhenrcsortingtoa dilution procedure, though somewhat smaller Dilution filtration, on the other hand, as a general rule is normally practiced at ordinary room temperatures. e. g., 70 F.

The time of contact, 1. e., the rate of flow through a given amount of adsorbent material, such as baumte, should be so adjusted that the filtered stock issues with the desired color. When practicing dilution filtration, the time of contact between the hydrocarbon mixture and the bauxite preferably should be somewhat longer than that used in straight filtration. Time of contact may be adjusted by suitably controlling the rate of flow.

Prior to the calcination of a spent bauxite, in order to condition the same fo reuse, it is a prerequisite to successful regeneration to remove excess retained hydrocarbon material by washing with a suitable solvent, such as naphtha and the like. This elimination of retained hydrocarbon material is an important factor in the regeneration of the bauifite. The oxidation of hydrocarbon matter as well as of carbonaceous ,matter derived from its carbonization involves an exothermic reaction which, in the oxidative calcination of bauxite containing retained hydrocarbons, will give rise to overheating, thus causmatter to a minimum by allowing two to three percent and preferably 2.5% of the so-called naphtha extractable matter to remain on the bauxite. "Though this.v percentage of naphtha extractable matter sov remaining includes coloring matter and a small amount of retained hydrocarbon matter, it is insufiicientto interfere with the subsequent oxidative calcination of the bauxhe so as to impair its regenerated adsorptive efficiency by overheating.

In the practical removal of retained 'hydrocarbon material in accordance with our discovery, we prefer to proceed in the following manner: Sufiicient naphtha is addedto the spent bauxite while the same is still on the filter or, if desired, in a separate receptacle to thoroughly soak or wet the same. After this soaking process the spent bauxite thus saturated with naphtha is allowed to stand until the naphtha commences to separate from the bauxite particles. Upon the completion of the soaking period, an additional amount of naphtha is then percolated through the naphtha-saturated adsorbent. We have found it of advantage to use from 230 to 235 ing considerable impairment of the adsorptive emciency of the bauxite, including high friability and excessive formation and/or retention of dust.

When filtering a crude hydrocarbon material through an activated or reactivated bauxite, the adsorptive afiinity of the latter for coloring matter is much greater than for the other components of said material. The material most tenaciously held by or upon the surface of the bauxite particles, consists almost entirely of coloring matter. Removal of coloring matter from the bauxite may be effected by special solvents or by oxidation. Beyond these adsorbed layers of coloring matter, there are other layers containing coloring carbons constitute the retained oil which is re- 00 movable by a naphtha or the like wash.

When treating a spent bauxite with a suitable solvent such as naphtha or the like to thereby remove the retained hydrocarbon matter, a considerable portion of the loosely bound coloring 65 and preferably not in excess of 240 gallons of naphtha per ton of bauxite for the total treatment including the soakage. We prefer to use approximately $4; of this amount for the soaking operation. For the purpose of obtaining best results we prefer to maintain a temperature of from about 120 to about 150 1'2, and preferably of 130 F., during the soaking as well as the percolation period. A suitable naphtha that may be used in accordance with the afore-outlined procedure is preferably one having the following characteristics:

A. P. I. gravity ..'..degrees 58- 60 Initial boiling point F 160-180 10% oh at .F 236 ofi at. F 264 90% oil at .F 308 End point F 360-390 When using a straight filtration process, i. e., without the expedient of dilution, much larger amounts of hydrocarbon material are retained by the bauxite, due to the usually relatively high viscosity of such material, than is the case when practicing dilution filtration. In this instance. it is advisable to insert the step of passing air through the bauxite to thereby remove part of the retained hydrocarbon material before the naphtha washing step. In most cases, the air blowing is continued until no further displacematter such as that contained in increasing ,con-

centrations adjacent the. sphere of adsorption for coloring matter, is removed together with the hydrocarbon fraction. If the naphtha wash should then be added to further quantities of adsorbed coloring affecting ment of retained hydrocarbon matter by the air is effected.

After the completion of the naphtha wash a certain amount of the naphtha remains on the bauxite and must be removed. This removal of remaining naphtha is accomplished by a steaming step, preferably under pressure, which is continued as long as the issuing steam contains any perceptible odor of naphtha. It is requisite, however, to use dry or superheated steam so as to prevent the removal of adsorbed coloring matter by condensed water.

When practicing the naphtha wash in accordance with the atom-prescribed conditions, the socalled washout, i. e., naphtha solution of the re- I tained hydrocarbon material, contains a minimum of coloring matter, and will yield a hydrocarbon stock that may be added to the subsequently to be filtered stock without appreciably the color of the same. In the case tion.

of dilution filtration, the washout is directly added to the filtered stock whereas in straight filtration the naphtha is removed by distillation and the remaining oil is then added to the original filtering stock.

Where hydrocarbon materials, solid or semisolid at ordinary temperature, such as parai'iln and petrolatum and the like, are to be subjected to bauxite treatment, they may be either percolated through this material in molten condition or dissolved in a suitable solvent, being as a general ruletreated'in either case in the same manner as ordinary liquid hydrocarbon mate- In the accompanying drawings we have set forth typical illustrations of procedures which may be employed in accordance with our inven- Figure 1 is a diagrammatic representation of bauxite activation in accordance with our invention.

Figure 2 is a diagrammatic representation of the activation of bauxite and simultaneous stabilization thereof in accordance with our invention, and

Figure 3 is a diagrammatic showing of a percolation treatment of a hydrocarbon material through an adsorbent bauxite and the regeneration of the latter.

As shown in Figure 1, the raw bauxite ore of suitable composition and of a mesh size of preferably between 20 and 80 mesh is placed in a calcination furnace, such as a l2'-hearth Herreshoif furnace. Heat is applied to the' various hearths preferably in such manner that the tem-'- peratureoftheoreoneachhearthisraisedby increments of approximately 100 F., until the 7 preferred temperature of 1200 F., is reached on the last hearth. During the calcining operation 'sllmclent air is admitted to maintain at all times andinallpartsofthefurnacegoodoxidizing conditions, and the hearth arms are preferably rotated at a speed of approximately 6 R. P. M. while the throughput is preferably reg lated in such manner that not more than approximately atwoinehlayeriscarriedbythearms. The

average mesh content of the original ore should preferably be the followinz:

' robzerv 'Ihecsicinedoreasitismesfromthefumaee atatempemtureogfrommto 1000-I".,ispr eferablypsssedintoandthrousha cascadetowenintothedischsrseendofwhicha bisst'of air of an approximste velocity of 5 feet/sec. is introduced. The cascade towerlis preferablyapproximstelywfeethilh; Whilethe bauxiteispassinsthroushthistoweratatemr -peraturebetween500andl000'1".,thetemperatureofthesirmrrentismsintsinedbetwe'en 150 andzfionJaniuh'omthetopofthetowerat.

atemperatmeinexcessofmfr. 'lhebauxite dustearriedambrtheairisdepositedinabin ortankattachedtotheupperendofthscascade 6 a,soo,o17

passedintoastoraget'ankordirectlyintothe filter towers.

The treatment of the bauxite in the aforedescribed manner results in a dimunition of 5 particle size, which, after its processing, is reflected in substantially the following mesh content:

A typical composition or a suitable bauxite ore 20 as compared with its composition after activation is illustrated in the following table:

Table VI Bauxite. Activated on bauxite Pu ses! Pascal Moistureloss 0110 C... 1.0 30, Combinedwater 420.0 1.5 Sol bleslnminauAlgO 66.0 no Solubloironss FBIOL- 6.0 .0 Soluble titanium as TiO;

Insoluble rsddum.

In apractical embodiment of the stabilization procedureasshowninl'lsure2,thebauxiteore of the same characteristics mesh size and mesh contents l8 described above in connection with I Figure 1, is placed into a suitable furnace, preferably of the type previously described. Heat is applied to the various hearths by means of richly adjusted as burners, and the temperature of the ore is preferably raised on each hearth by' in-- crements of approximately 1'5, until a maximum temperature of 600' r. is obtained and maintainedon at least the lastthi'eetofmir hearths. Allairisexcludedwherebyareducins atmosphere obtains suii'icient to transform the 5o fe'rriferous into paramasnetic matter. The reduced" bauxite is then passed throuah ma netized rollstowhich the"para-maaneticfractioh adheres. The para-magnetic matter is. continuouslydiscardedfromtherollswhilethebauiwiteof reduced iron contentis subjected to'sn oxidative calcination treatmentinthessmemsn nerwset forth in with l'iaurel.

Themeshcont'aitofthestabilisedbauxits as itissuesfromthscascadetowerisasfollowsz-i.

A ty ncalcomposition r suitable bauxite ore as compared with-itscunposition-aiter-stabilisatower and the discharge dedusted bauxite is tionsndsctivatlonissiveninthefoliowinstable:

Table VIII Example I A Mid-Continent bright stock was respectively uxi s mm percolated through a bauxite activated and debalm dusted in accordance with our invention and P m P t through a bauxite activated without removal of adhering dust particles, at a temperature of 250 ttiltffiiitififlifi::: "13:: 25:3 "its a, and under atmospheric pressure. There; Stittifittifiti'fdliif: 2:1: 2:3 i3 swim bauxites Wssessed the following Soluble titanium as TiOL. 1.0 1.0 acteristics: Insoluble residue..- 8.0 1:15

Gram Screen analysis In the percolation of hydrocarbon oil through u ty an adsorbent bauxite and the subsequent regen- 0x130 01140 Onfiil On80 eration ofthe latter as diagrammatically illustrated in Figure 3, the adsorbent bauxite suitably Per Per Per Per Per conditioned in accordance with either one of the f fi?ffff?f I, 108 25 g; g procedures outlined in Figures 1 and 2 is placed g g bauxite dust in a filtering tower. The hydrocarbon oil to be m e 94 49 23 22 2 refined is permitted to percolate through the bed of the adsorbent bauxite. The bauxite durin the filtration is maintained between 130 and 400 F., and preferably at 250 F. The filtrate issues in a. decolorized condition. The filtration is con- A comparative analysis of the qualities of the aforementioned stock before and after filtration through the respective bauxites is given in the following table:

ducted in a continuous manner until the issuing 25 Table oil commences to show an impairment in color.

This indicates that the bauxite has substantially Filtered lost its adsorptive emciency for coloring matter a l? through and has become substantially spent. The filtra- 0,181,181 wflvat ed fl gg tion is then discontinued and the adsorbent now gg ffg dusted containing coloring matter and retained hydrobauxite carbon oil. is blown with air, thereby to re- 0 move a portion Of the retained Oil. The thusly ga y gg -1:21:11 APL: removed hydrocarbon oil is returned to the origiyg go "1; g 22 g nal hydrocarbon oil stock while the so treated bauxite is subjected to a naphtha. wash under carbon test M conditions as hereinbefore described, which will Example H leave on the adsorbent from 2 to 3% of naphtha extractible material. The washout containing naphtha and hydrocarbon oil may be, if desired, subjected to a distillation and the recovered hydrocarbon oil returned to the original filtering stock, while the naphtha may be returned to the wash. The bauxite now containing coloring matter and retained naphtha is subjected to a steaming step, resulting in a steam extract containing naphtha, water, and some hydrocarbon material which, by settling and distillation, is separated into its component parts which are returned to their respective containers, the water being drawn off. The bauxite containing adsorbed coloring matter is then subjected to oxidative calcination in substantially the same manner and under substantially the same conditions as described in the activation and stabilization of a bauxite in connection with Figures 1 and 2. The resulting reactivated bauxite is now ready for reuse and returned to the filtering tower. The conditioning of the bauxiteup to and including the steaming step is preferably carried out in situ. While the regeneration of the bauxite may be accomplished in situ, we prefer to remove the bauxite from the filtering tower and subjectthe' same to the oxidative calcination treatment in a suitable furnace as hereinbefore described We have found that the percolation process in accordance with our invention is suitable for the refining of petroleum oils including those of parafiinic, naphthenic and mixed base crudes and particularly residua derived from Pennsylvania type petroleum oils. In the following, we have set forth examples for purposes of illustration without limiting ourselves to the precise materials or the conditions of temperatures or pressures or to the amounts specified.

hering dust particles at a temperature of 250 and at atmospheric pressure. The respective 45 bauxites possessed the following characteristics:

alysis oi the properties of the stock before and after filtration through the re ctive bauxite's:

Table X Original broadly all inherent novelty.

Thei'ollowing table shows a comparative an- I We claim: a 1. The process of refining petroleum hydrocarbons, which comprises bringing said hydrocarbons into intimate contact with thermally activated bauxite predominating in particles of a particle size within the range of 20 to 80 mesh, which have been contacted at a temperature of from 1000 F. to 1200 F. with a current of preheated air having a velocity of from 4 too feet per second to substantially free said particles of adherent relatively finer particles inseparable therefrom by screening, said air being at a temperature of from 120 F. to 220 F. at the point of first contact with said bauxite and at a temperature of from 200 F.

to 250 F. at the point of last contact with said' bauxite.

2. The process of refining petroleum hydrocarbons which comprises bringing said hydrocarbons into intimate contact with thermally activated bauxite predominating in particles of a particle size within the range of 20 to 80 mesh which has The process of refining petroleum hydrocarboos which comprises brinsingsaid hydrocarbons into intimate contact with thermally activated 5 been contacted at a temperature 0! from 1000 l".

to 1200' 1'. with a current of preheated air havingavelocityoffrom 4 to6feetpersecondtosubstantialiy free said particles of adherent relative- 1y finer particles inseparable therefrom by. screeni s, said airbeingpreheatedto a temperaturebetween 1''. and 220' 1'. prior to contacting with the bauxite.

4. The process of refining petroleum hydrocarbons-which comprises brinaina said hydrocarbons into intimate contact with thermally activated bauxite predominating in particles of a particle sizewithintheranzeof20to80meshwhichhas been contacted at a temperature of from 500 F. to 1600? F. with a current of preheated air having a velocity of from 4 to 6 feet per second to substantially free said particles of adherent relatively finer particles inseparable therefrom by screening, said air being preheated to a temperature between 120 1?. and 220' 1''. prior to contacting with the bauxite. v

FERDINAND W. BRE'I'H. ANTHONY KINSEL. 

